Hologram identification device
First Claim
1. An identification device which incorporates a multi-colour hologram, the colours of which are visible by reflection of incident natural light, said hologram including a film emulsion which has been permanently deformed selectively in differing areas of the hologram, thereby to produce the multiple colours.
0 Assignments
0 Petitions
Accused Products
Abstract
An identification device in the form of a security card or anti-counterfeiting label which comprises a hologram visible by reflection in incident natural light, the film emulsion having been permanently deformed so that the interference fringe spacings differ from those in a non-deformed emulsion, thereby to change from one part of the hologram to another the wavelength of light which is visible by reflection from the hologram.
-
Citations
13 Claims
-
1. An identification device which incorporates a multi-colour hologram, the colours of which are visible by reflection of incident natural light, said hologram including a film emulsion which has been permanently deformed selectively in differing areas of the hologram, thereby to produce the multiple colours.
- 2. An identification device which incorporates a hologram having layers of interference fringes lying generally parallel to the film substrate and being visible by reflection of incident natural light, said hologram including a film emulsion which has been permanently deformed selectively to alter the spacings between the layers of interference fringes in one region of the hologram from the spacings which exist in another region thereof, thereby to change the wavelength of light visible by reflection from said one region of the hologram as compared to said another region.
- 10. A method of producing an identification device which incorporates a hologram having layers of interference fringes lying generally parallel to the film substrate and being visible by reflection of incident natural light, the method comprising the steps of forming layers of interference fringes lying generally parallel to a film substrate, said layers being formed to be visible by reflection of incident natural light, and permanently deforming a film emulsion selectively to alter the spacings between the layers of interference fringes in one region of the hologram from the spacings which exist in another region thereof, to thereby change the wavelength of light visible by reflection from said one region of the hologram as compared to another region thereof.
Specification